diff --git a/modules/system/system.test b/modules/system/system.test
index 2865bbb..581b3f1 100644
--- a/modules/system/system.test
+++ b/modules/system/system.test
@@ -1107,6 +1107,8 @@ class PageNotFoundTestCase extends DrupalWebTestCase {
 
     $this->drupalGet($this->randomName(10));
     $this->assertText($node->title, 'Found the custom 404 page');
+
+    $this->fail('This is a test failure.');
   }
 }